Friday, September 5, 2014

Chilly at New Ivotuk CRN

I couldn't resist a brief post about the chilly temperatures being reported today from the new high-quality CRN station at Ivotuk on the north side of the Brooks Range. The new station has been in operation since mid-June and promises to supply a wealth of interesting data in years to come. This morning the temperature dropped to 6 °F there, and the chill in the surrounding area is evident from the VIIRS I05 band thermal infrared image provided by the Suomi NPP satellite at 4:20 am AKST today (click on the image for a larger version).

Kotzebue Sound is visible in the lower left and the Yukon River in the lower right; darker shades are colder, so unfrozen ocean, lakes, and rivers appear white. Interestingly, the Brooks Range river valleys were warmer than the high terrain this morning, which I assume must be because the valley bottoms are snow-free, while most of the higher terrain is snow-covered. However, an exception to this is seen near Ivotuk, as some of the high-elevation valleys just to the southeast of Ivotuk were very cold.

The table below shows the five-minute temperature observations from the Ivotuk CRN station since midnight local time.

[Update: it appears there is no credible historical report of a temperature this low so early in the season in Alaska. More investigation might be warranted to confirm this. I expect the Ivotuk station will set many new records of this sort in coming years.]

4 comments:

Been by there a few times in a floatplane 30 years ago, abandoned by then, now it's a research focal point. Insulated runway from the '70's...quite a feat of engineering. Nearby oil was the motive. Good they've kept it functional for the future.

If I may bring up a philosophical but perhaps somewhat practical point about records, since you mention the likelihood of this new station breaking some long standing records. Should these remote weather stations, such as this one, with only a few transient researchers or explorers be treated in the same way as the vast bulk of our climate history taken at inhabited places (manned obs until relatively recently)? I think we've always understood that the sampling of Alaska's climate is really a sub-sampling of non-random places, and that anyone with experience in the weather business here could point to areas on the map that are colder, windier, snowier etc than the "records" from inhabited places. There is a reason some of these places are not inhabited. Now technology allows sampling of previously unavailable data. I've seen references in the daily bulletin to state daily low temperatures being set at somewhere like "21 miles northwest of Venetie" and have to wonder if that temperature was read from the IR satellite image, and if so we've just changed the definition of the state daily low. Anyone else see this kind of shift as needing some attention?

Thanks for the great question. This issue is an interesting one for climate science, and I'm sure my colleagues here (Rick, Brian) will have some thoughts.

My feeling is that how we treat the data should be dictated by what questions we want to answer with it. If we're interested in long-term climate comparisons, then it's not appropriate to include data from previously inaccessible locations - but if the new observing platforms are maintained, then in 30 or 50 years we will be able to do some useful analysis. This is the point of the CRN program: to set up a high-quality network that can be relied on in future decades with the highest degree of confidence.

Apart from long-term climate analysis, however, remote weather stations help answer many questions about current conditions and modern or recent climate behavior, and here I think we absolutely should take advantage of the new data that's becoming available. For example, data from the Howard Pass RAWS in the past two winters has shown wind chill readings lower than I think many would have considered likely, and assuming the data is upheld after careful scrutiny, we have learned something interesting about Alaska's current climate. It's a vast and - as you point out - largely unsampled world, and there is so much to learn.

Rick would be able to speak to whether IR temperature estimates would ever be quoted in the context of a weather or climate summary, but I rather doubt it. Satellite data are indispensable for certain climate observations (e.g. sea ice), but for the local weather variables that we're all interested in, there's no substitute for ground-level instrumentation.